Summarize the following:
RGP lenses tend to be slightly less popular than soft lenses for a number of reasons, but there are many areas in which RGP lenses excel. An RGP lens will have the following benefits for most contact lens users:  Sharper vision than soft lenses provide Better visual clarity for some users with astigmatism Preferable for some users with presbyopia who require bifocals or multifocals Better fit and clarity for users with Keratoconus (cone-shaped cornea) Preferable for individuals who need contact lenses after refractive surgery Can be used for ortho-k procedures, in which lenses are worn at night to reshape the cornea Though RGP lenses are preferable for some users with specific needs, there are also some down sides to these lenses. Some users report that RGP lenses may have the following disadvantages:  They take longer to get used to and may be less comfortable. They will need to be worn regularly to become comfortable for the user (they can even become uncomfortable after a week of not wearing lenses). There is a greater risk of RGP lenses becoming dislodged during physical activities due to the smaller size of the lenses. There is a higher risk of discomfort or corneal abrasions due to the increased chance of dust/debris getting lodged under the lenses. They require greater care and maintenance than soft lenses; however, they tend to last longer, which may save you money in the long run. If you're on the fence about soft vs. RGP lenses, you may want to consider trying hybrid contact lenses. Hybrid lenses are made with a rigid, gas-permeable center but have a soft ring around the RGP component. This gives you the comfort of a soft lens while meeting the specialized needs some users have for a rigid lens.  Hybrid lenses can be used to correct nearsightedness, farsightedness, astigmatism, age-related loss of close-up vision, and keratoconus. Many users who need rigid lenses find that hybrid contact lenses are much more comfortable and easier to wear.

summary: Learn the advantages of RGP lenses. Know the disadvantages of RGP lenses. Consider hybrid contact lenses.


Summarize the following:
. Use slightly contrasting colors of paint, applied with a rag to get a textured appearance to the ceiling. You can also use a sponge in a similar manner to get another texture. You can mix joint compound into the paint in order to get a faux plaster look.  You can buy either a mix or the prepared compound. You will likely need a great deal of the material (at least 6 lbs of the prepared compound) but how much will depend on the area you are covering and how thick you want it to be. You can also use textured rollers to get other textures to your paint without having to apply multiple coats.  You can use shaggy rollers or other textured rollers. These should generally have examples of their final textures on the packaging.

summary: Texture the ceiling with a rag Texture the ceiling with thickened paint. Texture the ceiling with a special roller.


Summarize the following:
Newton’s second law of motion states that any object will accelerate when acted upon by a net or unbalanced force. In other words, if a force is acting upon an object that is greater than the forces acting in the opposite direction, the object will accelerate in the direction of the larger force.  This law can be summed up with the equation F = ma, where F is the force, m is the mass of the object, and a is acceleration. Using this law, we can calculate the force of gravity of any object on the surface of the earth, using the known acceleration due to gravity. On earth, the force of gravity causes objects to accelerate at a rate of 9.8 m/s2. On the earth’s surface, we can use the simplified equation Fgrav = mg to calculate the force of gravity. If you want a more exact approximation of force, you can still use the above equation, Fgrav = (GMearthm)/d2 to determine force of gravity. For this particular equation, you must use metric units. The mass of the object needs to be in kilograms (kg) and the acceleration needs to be in meters per second squared (m/s2). You must convert to these units before continuing with the calculation. For smaller objects, you can weigh them on a scale or balance to determine its weight in kilograms (kg). For larger objects, you will have to look-up the approximate mass in a table or online. In physics problems, the mass of the object will generally be provided to you. Once you have defined the variables of your equation, you can plug them in and solve. Be sure that all of your units are in metric and on the right scale. Mass should be in kilograms and distance in meters. Solve the equation using the proper order of operations.  Let’s use the same equation from above and see how close the approximation is. Determine the force of gravity on a 68 kg person on the surface of the earth. Make sure all your variables have the proper units: m = 68 kg, g = 9.8 m/s2. Write your equation. Fgrav = mg = 68*9.8 = 666 N. With F = mg the force of gravity is 666 N, while using the more exact equation yields a force of 665 N. As you can see, these values are almost identical.


summary: Understand Newton’s Second Law of Motion, F = ma. Know the acceleration due to gravity on earth. Use the proper metric units. Determine the mass of the object in question. Solve the equation.